NHBC confirms that during the first two years after legal completion of a new-build home, the builder, not NHBC, is responsible for rectifying problems arising from a failure to meet NHBC’s own building requirements, and that NHBC’s resolution service becomes available only once the builder’s complaints process has been completed.

Why this differs from adding one later

Most of the planning and building control guidance on this site concerns a conservatory added to an existing home, where the homeowner deals directly with an installer and, separately, with building control or a competent person scheme. Where a conservatory is included in a new-build home from the outset, bought as part of the whole property, a different framework applies: the structural warranty the developer arranges for the entire home, commonly an NHBC Buildmark policy, and the process for raising a defect runs through that warranty rather than a separate installer contract.

The two-year builder period

NHBC’s own guidance is specific about where responsibility sits in the period immediately after legal completion: during the first two years, the builder is responsible for rectifying problems arising from the builder’s failure to meet NHBC’s requirements, not NHBC itself. A defect in a new-build conservatory in this window, for example a leak, a sealing fault or an issue with how the space was constructed, is first and foremost a matter for the developer’s own aftercare or customer service team, in the same way any other defect in a new-build home is during this period.

How to report a problem

NHBC’s guidance says a homeowner should contact the builder as soon as reasonably possible after noticing a defect, and always within the two-year builder warranty period, keeping a record of that contact. This record becomes important evidence later if the builder does not resolve the issue and the homeowner needs to escalate to NHBC directly, since NHBC’s process depends on being able to see what was reported and when.

When NHBC steps in

NHBC describes its role as guaranteeing the builder’s obligations under the builder warranty, stepping in only if the builder fails to comply. Before that stage, specific conditions have to be met: the homeowner must have notified the builder within the warranty period, allowed the builder reasonable time to carry out repairs, gone through the builder’s full complaints process, and received the builder’s final written response. Only once these steps are complete does NHBC’s resolution service become available, rather than being a first port of call for any conservatory defect noticed in a new-build home.

The later structural period

After the two-year builder warranty period ends, Buildmark moves into an eight-year insurance period, covering physical damage caused by a failure to build to NHBC’s requirements, generally concentrated on structural elements such as foundations, load-bearing elements and the weatherproofing of the external envelope. A conservatory-related issue arising well into this later period is treated within this narrower, structurally focused part of the warranty, rather than the broader builder warranty process that applies in the first two years, and is less likely to be covered where the issue is cosmetic or a minor fault rather than a genuine structural defect.

Checking which warranty applies

NHBC is one of several structural warranty providers used across new-build housing in the UK, and a home built under a different provider follows that provider’s own equivalent process rather than NHBC’s. Confirming which warranty applies to a specific new-build property, and keeping the relevant policy booklet and certificate, is the reference point for what is and is not covered for that conservatory, rather than assuming the process described here applies automatically to every new-build home.

FAQs

Does NHBC deal with a new-build conservatory defect straight away?

No. NHBC says the builder is responsible for rectifying defects during the first two years, with NHBC’s resolution service acting as a backstop only after the builder’s own complaints process has been exhausted.

What does a homeowner need to do before NHBC will get involved?

Notify the builder within the warranty period, allow reasonable time for repair, complete the builder’s complaints process, and receive its final written response.

Does the later eight-year insurance period cover any conservatory issue?

It is focused on structural defects such as foundations and weatherproofing, so a cosmetic or minor fault arising in this later period is less likely to be the kind of issue it is designed to cover.

Is this the same as the warranty on a conservatory added to an existing home?

No. A conservatory added later is usually covered by the installer’s own guarantee and any insurance-backed warranty, a separate arrangement covered elsewhere on this site.

Bottom line

A conservatory included in a new-build home is generally covered by the same structural warranty as the rest of the property, and under NHBC’s Buildmark, the builder, not NHBC, is responsible for defects during the first two years, with NHBC’s resolution service available only once the builder’s own complaints process has been completed. The later, structural insurance period is framed around defects like foundations and weatherproofing rather than minor faults. This is general information, not advice on a specific policy; the individual Buildmark policy booklet and certificate confirm what applies to a particular home.

Sources

This guide draws on the following primary sources, current as of 22 September 2026:

• NHBC, “In the first two years of the policy”

Related guides

Compare Conservatories is an independent guide. We may earn a fee from some links; this never affects what we write. This article is general information, not legal or planning advice on any specific property — always confirm requirements directly with your local planning authority.